1. Field of the Invention
This invention relates to aircraft in general and more particularly to aircraft having rotating airfoils.
2. Description of the Prior Art
It is highly desirable to produce aircraft which is energy efficient; which is highly maneuverable; which can take off vertically; which can hover; and in which there is no mechanical linkage and therefore no wear between the "rotor" and the main body, i.e., the fuselage of the aircraft.
Flight characteristics of the annulus, also known as the gliding ring, is becoming better known due, in part, to the research of Alan Adler which resulted in production of a ring composed of plastic and rubber and known by the trademark Aerobie.RTM.. U.S. Patents providing disclosure of these rings having highly efficient aerodynamic characteristics for level and lengthy flights include U.S. Pat. Nos. 4,456,265 and 4,560,358. Numerous other patents, some of which are cited in the above enumerated patents, show a large variety of aerial gliding rings. The patents of Adler disclose an aerodynamic annulus having low aerodynamic drag, producing straight and level flight for great distances considering the low propulsive forces involved.
Magnetic levitation, while relatively new in the art of railway transportation, has proven effective at supporting a moving device, i.e., a vehicle, relative to a fixed track or rail, to produce an essentially friction-free levitation system. Two systems are now in use. One system, known as the Maglev system, works on the basis of magnetic attraction and the other system works on the basis of magnetic repulsion. In the first system, electromagnets attached to the vehicle are pulled upward toward an overlying metal rail. Strength of the electromagnetic field is controlled by controlling the current flow through the electromagnets and therefore the gap between magnets and rail can be conveniently controlled. In the repulsive system, now used on levitated trains in Japan, overlying electromagnets affixed to the vehicle induce electric currents in the track coils, causing the track itself to become a temporary electromagnet. The repulsive system generally requires supercold, superconducting electromagnets and is effective only upon movement of the vehicle relative to the track.
Helicopters utilize rotors, i.e., rotating airfoils to produce lift. No aircraft is known which utilizes a rotating annulus, and a rotating aerodynamic annulus, in particular, which is not mechanically connected either directly or indirectly to the fuselage.
Conventional aircraft having low aerodynamic drag either require long take-off and landing strips or must reduce drag by mechanically reducing the airfoil surface during flight. Conventional aircraft which hovers, such as helicopters, are incapable of high speed and current jet propulsion type of hovering aircraft, capable of vertical take-off and landings, are unstable, having no gyroscopic effect, and highly inefficient. No aircraft is known which is capable of hovering and yet accelerating at great speed in any selected direction, and no aircraft is known which has an annulus or rotor which is mechanically disconnected from the main body or fuselage to produce a substantially friction free bearing.